A ball grid array (BGA) is a type of surface-mount packaging (a chip carrier) used for integrated circuits. BGA packages are used to permanently mount devices such as microprocessors. A BGA can provide more interconnection pins than can be put on a dual in-line or flat package. The whole bottom surface of the device can be used, instead of just the perimeter.

I gotta' problem...('course you do Steve, or you wouldn't be bugging the TechNet now would you?) I had a phone call from a acquaintance of mine wanting to bring two prototype boards over to rework a BGA socket, (actually there's two on each board). No problem I said, bring em' on over. BOY O' BOY! Did I ever open my big yap this time! These sockets aren't like anything I've ever reworked before.

They're from a company called CTI, and they're called "Z-Lok" sockets, and they're surface mount. They've got this big beefy plastic housing that goes all the way down almost to the surface of the PCB, and has a little metal handle off to one side that actuates some little "arms" inside the socket that grab each ball on the BGA for good contact, but won't deform the balls so you can still use the BGA directly on a board after being in the socket if you wanted to.

The problem is that the socket has two locating pins on the bottom, which are used to accurately locate the socket (into holes drilled in the fab) when the board was first built.

There was a big time screw-up by either the fab vendor, the board lay-out person, or the dimensional drawing for the socket itself, but what has happened is that the BGA's contact pins are now soldered one row off! I'm being asked if I can pull this socket up, clip the plastic pins off, and put it back down on the board the way it's supposed to go...sounds like fun huh? This board is 12.5" X 18.5" and .065" thick...and the sockets are in the middle of the board.

I called back to CTI (They're in Indiana, but closed now) to talk with somebody there to find out how to rework one of these monsters...if it's possible.

I personally think that the socket is not meant to be reworked, it's a test socket and has to cost at least a hundred bucks or so. I think that once they're soldered down that's it. But I thought I'd ask ya'll to see if any of you have ever had to attempt something like this. There's only two of these boards, I don't wanna take a chance turning em' into scrap if I can help it...